May-June 2013

Eastern North Pacific Hurricanes 2012: An Average Season

by Richard J. Pasch

There was a near-average amount of tropical cyclone activity during the 2012 eastern North Pacific hurricane season. Of the 17 tropical storms that formed, 10 became hurricanes and five reached major hurricane strength (category 3 or stronger on the Saffir-Simpson Hurricane Wind Scale). In comparison, the 1981–2010 averages are about 15 tropical storms, eight hurricanes, and four major hurricanes. Although the numbers of named storms, hurricanes, and major hurricanes were slightly above average, in terms of the Accumulated Cyclone Energy (ACE) index, which is a measure that takes into account both the strength and duration of the season's tropical storms and hurricanes, 2012 had about 93 percent of the long-term median value of ACE. Most of the eastern Pacific tropical cyclones were spawned by tropical waves. Figures 1 and 2 depict the tracks of the 2012 eastern Pacific tropical storms and hurricanes. As is typical for this basin, most of the tropical cyclones remained offshore of the Mexican and Central American coasts. However, Hurricane Carlotta crossed the southern coast of Mexico in late June, bringing category 2 hurricane conditions to the coast. It was also the easternmost landfalling hurricane in the eastern Pacific since reliable records began in 1966. Paul caused some damage in Baja California Sur, Mexico, although it degenerated to a post-tropical cyclone prior to making landfall in that state.